Aging of nuclear glass analogues Aurélie Verney-Carron Since 2010: Assistant Professor at LISA, France 2009-2010: Post-doc at CRPG on Li isotopes to trace basaltic glass alteration 2005-2008: PhD at CEA on the Study of archaeological analog for the validation of nuclear glass long-term behavior models Joint ICTP-IAEA International School on Nuclear Waste Vitrification, 27 Sept. 2019
Objectives of analogs study q To know the long-term alteration C A REASONING BY ANALOGY Ancient glass Nuclear glass (short-term alteration) (short-term alteration) • A is similar to C in certain known respects. • A has some further feature B. ? B • Therefore, probably, C also has Ancient glass Nuclear glass the feature B. (long-term alteration) (long-term alteration) ü Different examples : long-term durability of natural glasses, retention of transition elements used as colorants in stained glass windows, contribution of cracks of Roman glass blocks, … ü It requires to demonstrate the analogy between the different glasses
Objectives of analogs study q To validate the predictive capacity of alteration models ?
Studies of ancient glasses Basaltic glass Ewing (1979, 2001) Allen (1983) Birchard (1984) Roman glass (shipwreck) Byers et al. (1985) Lutze et al. (1985) Grambow et al. (1986) Ewing and Jercinovic (1987); Jercinovic and Ewing (1988) Buried archaeological glass Cowan and Ewing (1989) Crovisier et al. (1989; 1992) Macquet and Thomassin (1992) Saint-Denis Embiez Iulia Felix Murakami et al. (1989) Sterpenich and Libourel (2001, 2006) Verney-Carron et al. (2008, 2010a,b) Arai et al. (1989) Ryan et al. (in prep) Werme et al. (1990) Strachan et al. (2014) Morgenstein & Schettel (1994) Techer et al. (2001, 2001a,b) Vitreous slags Parruzot et al. (2015) Ducasse et al. (2018) Stained glass windows Michelin et al. (2015) Obsidian Sterpenich and Libourel (2001, 2006) Vitrified forts Chondrites Sjöblom et al. (2013) Magonthier et al. (1992) Rani et al. (2013, 2015) Strachan & Pierce (2010) PNNL-19752 Report Weaver et al. (2016) Morlok and Libourel (2013) Tektites Libourel et al. (2011)
Order A- NATURAL GLASSES I. Volcanic glasses II. Properties: long-term durability III. Analogy between basaltic glass and nuclear glass IV. Analogy between obsidian and nuclear glass V. Primitive meteorites (chondrites) B- HUMAN-MADE GLASSES I. The stained glass windows II. Vitreous slags : interactions glass / iron III. Roman glass alteration modeling IV. Pre-viking Swedish hillfort glass / LAW glasses
A- Natural glasses
I. Volcanic glasses Volcanic rocks are formed by the fast cooling of magma (lava) at the Earth surface in different geodynamic contexts.
The composition influences the viscosity and the vitrification. Glass < high viscosity (to inhibit the crystallization) + sudden cooling to chill the material to a glass
BASALTIC GLASS North Atlantic LIP Low viscosity à high Siberian traps cooling rate (oceanic Iceland seafloor, subglacial volcanoes) Columbia OBSIDIAN River Deccan traps high viscosity but rare Afar Parana Pillow lavas in Iceland Main locations of natural glasses: oceanic seafloor and Large Igneous Provinces (LIP) (vitreous crust) Hyaloclastites
II. Properties : long-term durability Richet (2009) Verre plagioclase glass pyroxene Rocks from Figeac (Lot, France) – 280 My Þ Old natural glasses despite tectonic and erosion
Parruzot (2015) Initial rate (lab) at 5°C 1 µm / y 1 µm / 10000 y 1 µm / 1 My Þ The apparent alteration rate decreases with time. Þ The field alteration rate (confined medium) is lower than the lab alteration rate.
Parruzot et al. (2015) r r = 9.6·10 -6 g/m²/d at 90°C r r = 4.0·10 -6 g/m²/d at 30°C D = 2.5·10 -25 g/m²/d at 90°C D = 4.7·10 -26 g/m²/d at 30°C Þ Measurement of the residual rate using a t-dependent law and Na diffusion coefficients using a √t law
Parruzot (2015) Initial rate (lab) at 5°C Þ Extrapolation of a linear residual rate measured at the laboratory consistent with ancient samples
III. Analogy between BG and NG • Phenomenology NUCLEAR GLASS BASALTIC GLASS Alteration front Gel palagonite Fibrous palagonite TEM image of an Icelandic basaltic glass (0,1 My) [Crovisier et al., 2003] Glass Smectites, calcite, oxides, zeolites) Smectites, zeolites From Gin et al. (2017) From Zhou & Fyfe (1989) TEM image of an oceanic basaltic glass Gin et al. (2001) Zhou et al. (2001) (10,1 Ma): saponite at 10 Å [Zhou et al., 2001]. Þ Similar alteration facies
• Kinetics NUCLEAR / BASALTIC GLASS Forward dissolution rate Residual rate r r (ISG) = 2·10 -4 g/m²/d (90°C) • r r (BG) = 9.6·10 -6 g/m²/d (90°C) at pH 7 • Parruzot et al. (2015) r r (BG) = 4·10 -3 g/m²/d (90°C) at pH 9,3 • Ducasse et al. (2018) Þ Similar alteration rates Techer et al. (2000)
BASATIC GLASS Ducasse et al. (2018) T = 90°C, pH 7 (at 90°C) Si saturated solution t = 600 d Þ Complete depletion in Na, Ca, B Þ Si (~ Al, Ti) in the alteration layer (clays and amorphous silica) Þ Enrichment in 29 Si (// solution)
BASATIC GLASS Ducasse et al. (2018) ISG : Gin et al. (2015,2017) (a) Quick interdiffusion and hydrolysis → release of Na and Ca and B (b) Precipitation of clays (Si, Al, Fe, Mg, Ti) and SiO 2 (am) (c) The remaining silicate network dissolves and SiO 2 (am) precipitates (d) The layer of secondary phases grows up, sustaining glass dissolution COMPARISON WITH NUCLEAR GLASS Þ Differences with ISG Glass ISG: selective dissolution à passivating layer (glass alteration is limited by water diffusion) BG: congruent dissolution à clays (equilibrium) The dissolution is controlled by the hydrolysis of the glass network and is sustained by the precipitation of secondary phases. Þ A similar phenomenology but different mechanisms controlling the long-term alteration rate (due to composition)
IV. Analogy between obsidian and NG • Composition SiO 2 Al 2 O 3 Na 2 O K 2 O CaO MgO Fe 2 O 3 tot TiO 2 LOI 69.50 12.00 3.50 3.71 1.00 0.07 2.63 0.182 7.11 • Phenomenology: dioctahedral smectite Rani et al. (2013, 2015)
V. Primitive meteorites (chondrites) • Fe and Mg minerals, Si-Al glass, Fe-Ni metal and clays à glass / iron / clays (storage) • Different alteration stages between 50 and 150°C Morlok et al. (2013)
B- Human-made glasses
I. The stained glass windows • Archaeological stained glass (buried in soils) Sterpenich and Libourel (2001) Stained glass excavated from the site of Notre- Dame-de Bourg (Digne), 12th century Þ High retention of transition elements and heavy metals
• Stained glass weathered in atmosphere Sterpenich and Libourel (2001) Þ Partial retention of transition elements and heavy metals
• Analogy NUCLEAR GLASS T = 90°C Valle et al. (2010)
Verney-Carron et al. (2017) STAINED GLASS T = 30°C 1 month Dynamic conditions Pristine glass Gel layer Þ Indication on the long-term partition of transition elements and similar mechanisms far from saturation
II. Vitreous slags : interactions glass / iron De Combarieu et al. (2011) EXPERIMENT SON68 + iron (10 µm) + Bure argilite + water EXPERIMENT T = 90°C for 18 months T = 50°C SON68 + 2 x magnetite Synthetic clay- based groundwater SON68 + magnetite SON68 Comparison between experimental results (diamonds), modelling with sorption of Si (dashed lines) and sorption of Si + precipitation of iron silicates. Godon et al. (2013) Þ Formation of Fe-silicates Þ Iron increases glass alteration rate due to the Þ Alteration thickness = r 0 /2 Þ Iron sustains a high alteration rate precipitation of Fe-silicates
Michelin et al. (2013, 2015) VITREOUS SLAGS Site of Glinet (Normandy) Blast furnace 16th c. Soil saturated with anoxic water SiO 2 : 62 à 77 %, Al 2 O 3 : 5 à 9 %, CaO : 16 à 25 % Þ Analogy: vitreous slag / glass package and steel container
Siderite (Fe 1-x Ca x CO 3 ) Gel Fe-silicates Pristine glass Alteration thickness: ~ 20 µm (external cracks) / 2-6 µm (internal cracks) Þ Fe-silicates precipitation is a long-term mechanism but there is a drop in the alteration rate in cracks
III. Roman glass alteration modeling Alteration for 1800 years Morphological analogy In a stable environment (seawater at 15°C)
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ALTERATION Border zone (BZ) PHENOMENOLOGY Thick altered cracks • Smectites Smectites • 84 % of total alteration • Internal zone (IZ) 1 cm • Thin altered cracks (5-20 µm) • Hydrated glass (and smectites) Smectites • Cracks density 6x higher 16 % of total alteration • Hydrated glass Þ Low contribution of internal cracks to global alteration (+ sealing) Verney-Carron et al. (2008)
Na + H + SiO 2 diffusion pH saturation pH, Mg, CO 3 2- carbonates smectites Leached glass Glass Þ Need to model the coupling between chemistry and transport 31
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